VIGNA RADIATA ROOT ASSOCIATED MYCORRHIZAE AND THEIR HELPING BACTERIA FOR IMPROVING CROP PRODUCTIVITY

Abstract

Arbuscualr mycorrhizal (AM) fungi and symbiotic bacteria have a pervasive effect upon plant form and function. We investigated the possibility of enhanced grain yield in Vigna radiata, by applying Bradyrhizobium and Agrobacterium in combination with mycorrhizae as inoculum. A field experiment was conducted to study the effect of bacterial and arbuscular mycorrhizal inoculants on biomass, nodulation, total grain yield, nitrogen and phosphorus contents in grain of Vigna radiata. A significant increase in the biomass, nodulation, total grain yield, nitrogen and phosphorus contents was observed with the application of bacterial and arbuscular mycorrhizal consortium, reflecting the existence of synergistic relationships among the inoculants. Another set of experiment was carried out under controlled environmental conditions of growth room, to localize the bacterial cells in roots and nodules, through ultrastructure studies. Co-occupancy of mycorrhizae with Bradyrhizobium and Agrobacterium in Vigna radiata plant roots and root nodules was also evaluated in this study. This study illustrates that arbuscular mycorrhizae with bacterial inoculants as well as bacterial inoculants alone led to a significant increase in biochemical and physiological characteristic and this tripartite association can be exploited to be used as mix inoculum for enhanced legume crop production.